1. Technical Field
The present invention relates generally to an improved data processing system and in particular to a method and apparatus for managing a data processing system. Still more particularly, the present invention provides a method and apparatus for handling memory shortages in a data processing system.
2. Description of Related Art
Distributed computing involves the cooperation of two or more computers communicating over a network. These computers may range from personal computers to super computers. In a distributed computing environment, the network may connect machines located in a building or on different continents. With this type of cooperative computing, special function hardware or software may be made available over the network without having to duplicate this hardware or software on every node that requires access to this special function hardware or software. In addition, distributed computing allows many small workstations to work together rather than requiring a large workstation of equivalent power, which is often more expensive. For example, adding another small workstation to a distributed system can be faster and less expensive than bringing down a centralized system and replacing it with an upgraded system.
With these advantages in distributed computing, Open Software Foundation Distributed Computing Environment (DCE) has been provided as an industry standard set of computing technologies. DCE is able to run on all major computing platforms and is designed to support distributed applications in heterogeneous hardware and software environments. For example, DCE is available for use with Advanced Interactive Executive (AIX) operating system, which is available from International Business Machines Corporation. With DCE, a remote host may be monitored by an administrator to identify shortages in resources or to identify errors in execution, which may require intervention by the administrator.
Swap space is a virtual storage mechanism in which data in the main storage may be written to an auxiliary storage. The data may be written back into the main storage when needed. This mechanism typically involves a paging technique that writes active pages of a job to an auxiliary storage and reads pages of another job from the auxiliary storage into the main or real storage. In DCE, insufficient swap space on a machine may indicate that programs (e.g., resource monitors or tasks) on that machine may not complete. As a result, other processes running on the machine may contribute to the problem or may be unable to execute.
Therefore, it would be advantageous to have a method and apparatus to manage shortages of memory resources in a data processing system.
The present invention provides a method and apparatus in a distributed data processing system for managing memory in a data processing system within the distributed data processing system. Responsive to detecting a first level of memory shortage on the data processing system, a first set of monitors is automatically stopped on the data processing system. Responsive to detecting a second level of memory shortage on the data processing system, a second set of monitors is stopped on the data processing system. Responsive to detecting a ceasing of the memory shortage, all stopped monitors are automatically started. The present invention also provides for a method of controlling how the memory management capabilities are enabled and disabled.